Wound healing effect of flavonoid rich fraction and luteolin isolated from Martynia annua Linn. on streptozotocin induced diabetic rats

Therapeutic Potential of Luteolin for Diabetes Mellitus and Its Complications

The global prevalence of diabetes mellitus (DM) and its complications has been showing an upward trend in the past few decades, posing an increased economic burden to society and a serious threat to human life and health. Therefore, it is urgent to investigate the effectiveness of complementary and alternative therapies for DM and its complications. Luteolin is a kind of polyphenol flavonoid with widely existence in some natural resources, as a safe dietary supplement, it has been widely studied and reported in the treatment of DM and its complications. This review demonstrates the therapeutic potential of luteolin in DM and its complications, and elucidates the action mode of luteolin at the molecular level. It is characterized by anti-inflammatory, antioxidant, and neuroprotective effects. In detail, luteolin can not only improve endothelial function, insulin resistance and β-cell dysfunction, but also inhibit the activities of dipeptidyl peptidase-4 and α-glucosidase. However, due to the low water solubility and oral bioavailability of luteolin, its application in the medical field is limited. Therefore, great importance should be attached to the joint application of luteolin with current advanced science and technology. And more high-quality human clinical studies are needed to clarify the effects of luteolin on DM patients.

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Topical Administration of Teucrium polium on Diabetic Foot Ulcers Accelerates Healing: A Placebo-Controlled Randomized Clinical Study

Diabetic foot ulcer is one of the most devastating complications of uncontrolled diabetes. Although there have been advances in the management of diabetic foot ulcers, still diabetic foot ulcers are a major cause of many amputations in diabetic patients. Teucrium polium (T. polium) is widely used by folk medicine practitioners in Iran for the treatment of diabetic ulcers.The present study was designed to evaluate the safety and efficacy of topical T. polium ointment besides the standard treatment in diabetic foot ulcers.A total of 70 diabetic patients with foot ulcers grade 1 or 2 according to Wagner's scale were enrolled in this study. Patients were randomly divided into two groups. Patients in both groups received standard treatment for diabetic foot ulcers. In addition, group 1 received topical T. polium ointment, and group 2 received topical placebo ointment for 4 weeks. The T. polium and placebo ointments were rubbed twice daily two hours before the conventional dressing. The ulcer size, healing time, and laboratory tests were measured in both groups at baseline and end of the study after 4 weeks.Twenty-nine patients remained in the T. polium group and 26 in the placebo group until the end of the study. The mean surface area of ulcers was 3.52 ± 1.47 and 3.21 ± 1.67 cm2 in T. polium group and placebo group respectively at baseline which decrease to .717 ± .19 and 1.63 ± .72 cm2 respectively at the endpoint. The mean ulcer surface area was significantly lower in T. polium compared with the placebo group (p < .0001) at end of the study. Also, the number of patients that completely recovered in the T. polium group was significantly higher than the placebo group (p < .001) at the end of the study.The addition of topical T. polium ointment to standard treatment significantly improves the healing time of diabetic non-infected foot ulcers.

Insights into the mechanisms of diabetic wounds: pathophysiology, molecular targets, and treatment strategies through conventional and alternative therapies

Diabetes mellitus is a prevalent cause of mortality worldwide and can lead to several secondary issues, including DWs, which are caused by hyperglycemia, diabetic neuropathy, anemia, and ischemia. Roughly 15% of diabetic patient's experience complications related to DWs, with 25% at risk of lower limb amputations. A conventional management protocol is currently used for treating diabetic foot syndrome, which involves therapy using various substances, such as bFGF, pDGF, VEGF, EGF, IGF-I, TGF-β, skin substitutes, cytokine stimulators, cytokine inhibitors, MMPs inhibitors, gene and stem cell therapies, ECM, and angiogenesis stimulators. The protocol also includes wound cleaning, laser therapy, antibiotics, skin substitutes, HOTC therapy, and removing dead tissue. It has been observed that treatment with numerous plants and their active constituents, including Globularia Arabica, Rhus coriaria L., Neolamarckia cadamba, Olea europaea, Salvia kronenburgii, Moringa oleifera, Syzygium aromaticum, Combretum molle, and Myrtus communis, has been found to promote wound healing, reduce inflammation, stimulate angiogenesis, and cytokines production, increase growth factors production, promote keratinocyte production, and encourage fibroblast proliferation. These therapies may also reduce the need for amputations. However, there is still limited information on how to prevent and manage DWs, and further research is needed to fully understand the role of alternative treatments in managing complications of DWs. The conventional management protocol for treating diabetic foot syndrome can be expensive and may cause adverse side effects. Alternative therapies, such as medicinal plants and green synthesis of nano-formulations, may provide efficient and affordable treatments for DWs.

Multifunctional and theranostic hydrogels for wound healing acceleration: An emphasis on diabetic-related chronic wounds

Hydrogels represent intricate three-dimensional polymeric structures, renowned for their compatibility with living systems and their ability to naturally degrade. These networks stand as promising and viable foundations for a range of biomedical uses. The practical feasibility of employing hydrogels in clinical trials has been well-demonstrated. Among the prevalent biomedical uses of hydrogels, a significant application arises in the context of wound healing. This intricate progression involves distinct phases of inflammation, proliferation, and remodeling, often triggered by trauma, skin injuries, and various diseases. Metabolic conditions like diabetes have the potential to give rise to persistent wounds, leading to delayed healing processes. This current review consolidates a collection of experiments focused on the utilization of hydrogels to expedite the recovery of wounds. Hydrogels have the capacity to improve the inflammatory conditions at the wound site, and they achieve this by diminishing levels of reactive oxygen species (ROS), thereby exhibiting antioxidant effects. Hydrogels have the potential to enhance the growth of fibroblasts and keratinocytes at the wound site. They also possess the capability to inhibit both Gram-positive and Gram-negative bacteria, effectively managing wounds infected by drug-resistant bacteria. Hydrogels can trigger angiogenesis and neovascularization processes, while also promoting the M2 polarization of macrophages, which in turn mitigates inflammation at the wound site. Intelligent and versatile hydrogels, encompassing features such as pH sensitivity, reactivity to reactive oxygen species (ROS), and responsiveness to light and temperature, have proven advantageous in expediting wound healing. Furthermore, hydrogels synthesized using environmentally friendly methods, characterized by high levels of biocompatibility and biodegradability, hold the potential for enhancing the wound healing process. Hydrogels can facilitate the controlled discharge of bioactive substances. More recently, there has been progress in the creation of conductive hydrogels, which, when subjected to electrical stimulation, contribute to the enhancement of wound healing. Diabetes mellitus, a metabolic disorder, leads to a slowdown in the wound healing process, often resulting in the formation of persistent wounds. Hydrogels have the capability to expedite the healing of diabetic wounds, facilitating the transition from the inflammatory phase to the proliferative stage. The current review sheds light on the biological functionalities of hydrogels, encompassing their role in modulating diverse mechanisms and cell types, including inflammation, oxidative stress, macrophages, and bacteriology. Additionally, this review emphasizes the significance of smart hydrogels with responsiveness to external stimuli, as well as conductive hydrogels for promoting wound healing. Lastly, the discussion delves into the advancement of environmentally friendly hydrogels with high biocompatibility, aimed at accelerating the wound healing process.

Potential roles of circulating microRNAs in the healing of type 1 diabetic wounds treated with green tea extract: molecular and biochemical study

Background

Circulating miRNAs have been implicated in various aspects of diabetic wound healing, including inflammation, angiogenesis, and extracellular matrix remodeling. Thus, in alternative herbal medicine strategies, miRNAs will be potential therapeutic molecular targets in nonhealing wounds. These could be valuable elements for understanding the molecular basis of diabetic wound healing and could be used as good elements in bioinformatics.

Objectives

To elucidate the molecular mechanisms of microRNAs in association with apoptosis-inducing genes in controlling skin wound healing in diabetic wounds treated with green tea polyphenols (GTPs).

Methods

Green tea hydro extract (GTE) at doses of100-200 mg/ml was topically applied to the skin tissues of rats with T1DM induced by a single dose of streptozotocin (STZ; 100 mg/kg, in 0.01 M sodium citrate, pH 4.3-4.5) injected intraperitoneally for seven consecutive days to induce T1DM. The rats were treated with green tea for three weeks. A sterile surgical blade was used to inflict a circular wound approximately 2 cm in diameter on the anterior-dorsal side of previously anesthetized rats by a combination of ketamine hydrochloride (50 mg/kg, i.e., body weight) and xylazine hydrochloride. Afterward, the molecular roles of the circulating miRNAs miR-21, miR-23a, miR-146a, and miR-29b and apoptotic genes were determined by quantitative real-time PCR to evaluate Bax, Caspase-3, and Bcl-2 in wound healing. In addition, HPLC analysis was also performed to estimate the active polyphenols (GTPs) present in the hydro extract of green tea leaves.

Results

Wound healing was improved in diabetic skin wounds following treatment with GTE at doses of 100-200 mg/dl for three weeks. The wound parameters contraction, epithelialization, and scar formation significantly improved in a short time (14 days) compared to the longer periods identified in diabetic non-treated rats (20 days) and the standard control (15.5 days). Molecular analyses reported a significant increase in the levels of miR-21, miR-23a, and miR-146a and a decrease in the levels of miR-29b in green tea-treated diabetic rats compared to those in the standard control and STZ-diabetic non-treated rats. In addition, the molecular apoptotic genes Bax and caspase-3 significantly increased, and the BcL-2 gene significantly decreased following treatment with green tea polyphenols.

Conclusions

The data showed that active green tea polyphenols (GTPs) present in GTE significantly improved diabetic wound healing by controlling apoptotic genes and the circulating microRNAs miR-21, miR-23a, miR-146a, and miR-29b, which might be involved in cellular apoptosis and angiogenesis processes. Thus, to establish a future model for the treatment of diabetic wounds, further studies are needed to understand the potential association of these biological parameters with the wound-healing process in diabetic wounds.

Dehydrozingerone promotes healing of diabetic foot ulcers: a molecular insight

INTRODUCTION

One of the most common problems of diabetes are diabetic foot ulcers (DFUs). According to National Institute for Health, initial management of DFUs can decrease the complication of limb amputations and can improve the patient's quality of life. DFU treatment can be optimized with the help of multidisciplinary approach. Based on many studies, control of glucose levels in blood, antioxidant activity, reduction in cytokine levels, re-epithelialization, collagen formation, migration of fibroblasts are major phases involved in managing DFU. Dehydrozingerone (DHZ), has been known for its anti-inflammatory, antioxidant and wound healing properties.

METHODOLOGY

Three months high-fat diet and low dose of streptozotocin-induced type-II diabetic foot ulcer model was used to evaluate the effectiveness of dehydrozingerone. DHZ was given orally to rats for 15 days post wounding. TNF-α, IL-1β and antioxidant parameters like lipid peroxidation, glutathione reductase were estimated. Immunoblotting was done to investigate the effect of DHZ on the expression of ERK, JNK, HSP-27, P38, SIRT-1, NFκB, SMA, VEGF and MMP-9 in skin tissue. Histopathology was performed for analyzing DHZ effect on migration of fibroblasts, formation of epithelium, granulation tissue formation, angiogenesis and collagen formation.

RESULTS

DHZ decreased the levels of malondialdehyde, TNF-α, IL-1β and increased glutathione levels in wound tissue. Western blotting results suggested that DHZ activated ERK1/2/JNK/p38 signaling, increased expression of HSP-27, SIRT-1, VEGF, SMA thus facilitating the migration and proliferation of fibroblasts, angiogenesis and decreased inflammation. Masson Trichrome & histopathology showed an increase in collagen, epithelial and granulation tissue formation.

CONCLUSION

DHZ significantly accelerates the healing of diabetic foot ulcers in high fat diet fed plus low dose streptozotocin induced type-II diabetic Wistar rats.

Bisacurone gel ameliorated burn wounds in experimental rats via its anti-inflammatory, antioxidant, and angiogenic properties

PURPOSE

To investigate putative mechanism of wound healing for chitosan-based bisacurone gel against secondary burn wounds in rats.

METHODS

A second-degree burn wound with an open flame using mixed fuel (2 mL, 20 seconds) was induced in Sprague Dawley rats (male, 180-220 g, n = 15, each) followed by topical treatments with either vehicle control (white petroleum gel, 1%), silver sulfadiazine (1%) or bisacurone gel (2.5, 5, or 10%) for 20 days. Wound contraction rate and paw withdrawal threshold were monitored on various days. Oxidative stress (superoxide dismutase, glutathione, malondialdehyde, and nitric oxide), pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukins by enzyme-linked immunosorbent assay), growth factors (transforming growth factor-β, vascular endothelial growth factor C using real time polymerase chain reaction and Western blot assay) levels, and histology of wound skin were assessed at the end.

RESULTS

Bisacurone gel showed 98.72% drug release with a 420.90-442.70 cps viscosity. Bisacurone gel (5 and 10%) significantly (p < 0.05) improved wound contraction rate and paw withdrawal threshold. Bisacurone gel attenuated oxidative stress, pro-inflammatory cytokines, and water content. It also enhanced angiogenesis (hydroxyproline and growth factor) and granulation in wound tissue than vehicle control.

CONCLUSIONS

These findings suggested that bisacurone gel can be a potential candidate to treat burn wounds via its anti-inflammatory, antioxidant, and angiogenic properties.

Investigation of the Influence of Wound-Treatment-Relevant Buffer Systems on the Colloidal and Optical Properties of Gold Nanoparticles

Biocompatible gold nanoparticles (AuNPs) are used in wound healing due to their radical scavenging activity. They shorten wound healing time by, for example, improving re-epithelialization and promoting the formation of new connective tissue. Another approach that promotes wound healing through cell proliferation while inhibiting bacterial growth is an acidic microenvironment, which can be achieved with acid-forming buffers. Accordingly, a combination of these two approaches appears promising and is the focus of the present study. Here, 18 nm and 56 nm gold NP (Au) were prepared with Turkevich reduction synthesis using design-of-experiments methodology, and the influence of pH and ionic strength on their behaviour was investigated. The citrate buffer had a pronounced effect on the stability of AuNPs due to the more complex intermolecular interactions, which was also confirmed by the changes in optical properties. In contrast, AuNPs dispersed in lactate and phosphate buffer were stable at therapeutically relevant ionic strength, regardless of their size. Simulation of the local pH distribution near the particle surface also showed a steep pH gradient for particles smaller than 100 nm. This suggests that the healing potential is further enhanced by a more acidic environment at the particle surface, making this strategy a promising approach.

Antioxidant Activities of Natural Compounds from Caribbean Plants to Enhance Diabetic Wound Healing

Diabetic wound healing is a global medical challenge. Several studies showed that delayed healing in diabetic patients is multifactorial. Nevertheless, there is evidence that excessive production of ROS and impaired ROS detoxification in diabetes are the main cause of chronic wounds. Indeed, increased ROS promotes the expression and activity of metalloproteinase, resulting in a high proteolytic state in the wound with significant destruction of the extracellular matrix, which leads to a stop in the repair process. In addition, ROS accumulation increases NLRP3 inflammasome activation and macrophage hyperpolarization in the M1 pro-inflammatory phenotype. Oxidative stress increases the activation of NETosis. This leads to an elevated pro-inflammatory state in the wound and prevents the resolution of inflammation, an essential step for wound healing. The use of medicinal plants and natural compounds can improve diabetic wound healing by directly targeting oxidative stress and the transcription factor Nrf2 involved in the antioxidant response or the mechanisms impacted by the elevation of ROS such as NLRP3 inflammasome, the polarization of macrophages, and expression or activation of metalloproteinases. This study of the diabetic pro-healing activity of nine plants found in the Caribbean highlights, more particularly, the role of five polyphenolic compounds. At the end of this review, research perspectives are presented.

Horsetail (Equisetum hyemale) Extract Accelerates Wound Healing in Diabetic Rats by Modulating IL-10 and MCP-1 Release and Collagen Synthesis

Traditionally, Equisetum hyemale has been used for wound healing. However, its mechanism of action remains to be elucidated. For this purpose, a 40% ethanolic extract of E. hyemale was prepared. Phytochemical screening revealed the presence of minerals, sterols, phenolic acids, flavonols, a lignan, and a phenylpropenoid. The extract reduced the viability of RAW 264.7 cells and skin fibroblasts at all times evaluated. On the third day of treatment, this reduction was 30–40% and 15–40%, respectively. In contrast, the extract increased the proliferation of skin fibroblasts only after 48 h. In addition, the extract increased IL-10 release and inhibited MCP-1 release. However, the extract did not affect both TGF-β1 and TNF-α released by RAW 264.7 cells. The higher release of IL-10 could be related to the up-/downregulation of inflammatory pathways mediated by the extract components associated with their bioactivity. The extract inhibited the growth of Staphylococcus aureus and Escherichia coli. Topical application of the extract accelerated wound healing in diabetic rats by increasing fibroblast collagen synthesis. These results suggest that E. hyemale extract has great potential for use in the treatment of wounds thanks to its phytochemical composition that modulates cytokine secretion, collagen synthesis, and bacterial growth.

Luteolin intake is negatively associated with all-cause and cardiac mortality among patients with type 2 diabetes mellitus

BACKGROUND

Luteolin, a common flavonoid in our daily diet, has potent anti-diabetic effects. However, its prognostic impact on type 2 diabetes mellitus (T2DM) is still uncertain. This study aimed to clarify this association.

METHODS

In this prospective cohort study, 2,461 patients with T2DM were included from the National Health and Nutrition Examination Survey. Dietary luteolin intake was estimated by the type and amount of food consumed in a 24-hour dietary recall. All-cause and cardiac mortality were ascertained by National Death Index Mortality data (as of December 31, 2019). The association of luteolin intake with mortality risk was estimated by Cox proportional hazards model.

RESULTS

The median (interquartile range) luteolin intake was 0.355 (0.130, 0.835) mg/day. During the follow-up (median, 8.4 years), 561 all-cause deaths (including 136 cardiac deaths) were documented. Per-unit increment of luteolin intake (natural logarithm transformed) was found to reduce all-cause mortality by 7.0% (P = 0.024) and cardiac mortality by 22.6% (P = 0.001) in patients with T2DM. An inverse dose-response association was identified between luteolin intake (range: 0.005-9.870 mg/day) and mortality risk. The consistent result was also shown when stratified by age, gender, race, body mass index, HbA1c level, and T2DM duration. Moreover, luteolin intake increment was also shown to be associated with a lower C-reactive protein level at baseline (β =-0.332; 95% CI =-0.541, -0.122).

CONCLUSION

The current study confirmed that the dietary luteolin intake increment reduced all-cause mortality (especially cardiac mortality) in patients with T2DM, which may be attributed to the anti-inflammatory property of luteolin.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Wound healing properties of a new formulated flavonoid-rich fraction from Dodonaea viscosa Jacq. leaves extract

Background: Dodonaea viscosa Jacq. (D. viscosa) belongs to the family of Sapindaceae, commonly known as "Sinatha," and is used as a traditional medicine for treating wounds due to its high flavonoids content. However, to date there is no experimental evidence on its flavonoid-rich fraction of D. viscosa formulation as an agent for healing wounds. Objective: The present study aimed to evaluate the wound healing effect of ethyl acetate fraction of D. viscosa leaves on dermal wounds. Methods: The ethyl acetate fraction was produced from a water-ethanol extract of D. viscosa leaves and was quantitatively evaluated using the HPLC technique. The in-vivo wound healing ability of the ethyl acetate fraction of D. viscosa ointment (DVFO, 2.5%w/w and 5%w/w) was investigated in Sprague-Dawley rats utilizing an incision and excision paradigm with povidone-iodine ointment (5% w/w) as a control. The percentage of wound closure, hydroxyproline and hexosamine concentrations, tensile strength and epithelialization duration were measured. Subsequently, histopathology analysis of skin samples as well as western blots were performed for collagen type 3 (COL3A1), basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). Results: The ethyl acetate fraction of D. viscosa revealed flavonoids with high concentrations of quercetin (6.46% w/w) and kaempferol (0.132% w/w). Compared to the control group, the DVFO (2.5% and 5.0% w/w) significantly accelerated wound healing in both models, as demonstrated by quicker wound contraction, epithelialization, elevated hydroxyproline levels and increased tensile strength. Histopathological investigations also revealed that DVFO treatment improved wound healing by re-epithelialization, collagen formation and vascularization of damaged skin samples. Western blot analysis further demonstrated an up-regulation of COL3A, vascular endothelial growth factor and bFGF protein in wound granulation tissue of the DVFO-treated group (p < 0.01). Conclusion: It is concluded that flavonoid-rich D. viscosa ethyl acetate fraction promotes wound healing by up-regulating the expressions of COL3A, VEGF and bFGF protein in wound granulation tissue. However, extensive clinical and pre-clinical research on the flavonoid-rich fraction of D. viscosa is needed to determine its significant impact in the healing of human wounds.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.

Cedrus deodara: In Vivo Investigation of Burn Wound Healing Properties

Objective

Cedrus deodara (Roxb. Ex Lamb.) G. Don possesses various biological activities, which have been documented in modern and traditional medicine. In this study, burn wound healing activity of the methanol extract of C. deodara wood was evaluated via a burn wound model in Wistar rats.

Methods

The methanol extract of C. deodara was evaluated for the contents of phenolic compounds, flavonoids, and tannins. Also, its antioxidant activity was determined using the DPPH assay. Then, a topical ointment containing the methanol extract of C. deodara (10%) was used to evaluate the healing effects on a model of second-degree thermal burn in 4 groups of 7 rats within 21 days. In this respect, average wound surface area, wound closure, and various histological features were examined.

Results

Our findings revealed that the wounds treated with the methanol extract of C. deodara showed higher wound contraction (33.6, 87.1, and 93.4% on days 7, 14, and 21, respectively) compared with the positive control (27.6, 80.7, and 88.3% on days 7, 14, and 21, respectively) and the negative control (20.1, 77.9, and 80.2% on days 7, 14, and 21, respectively). According to the results from epitheliogenesis score, the number of inflammatory cells, neovascularization, and collagen density, good burn wound healing activity of the methanol extract of C. deodarawas demonstrated.

Conclusion

Using the methanol extract of C. deodara in an ointment formulation can be developed to prevent or reduce burn injury progression.

Influence of Acidic pH on Wound Healing In Vivo: A Novel Perspective for Wound Treatment

There has been little understanding of acidification functionality in wound healing, highlighting the need to study the efficacy of wound acidification on wound closure and cellular activity in non-infected wounds. This study is focused on establishing the healing potential of wound acidification in non-infected wounds. Acidic buffers, constituting either phosphoric or citric acid, were employed to modify the physiological pH of non-infected full-thickness excisional murine wounds. Acidification of the wound by acidic buffers was found to be an effective strategy to improve wound healing. A significant improvement in wound healing parameters was observed as early as 2 days post-treatment with acidic buffers compared to controls, with faster rate of epithelialization, wound closure and higher levels of collagen at day 7. pH is shown to play a role in mediating the rate of wound healing, with acidic buffers formulated at pH 4 observed to stimulate faster recovery of wounded tissues than pH 6 buffers. Our study shows the importance of maintaining an acidic wound microenvironment at pH 4, which could be a potential therapeutic strategy for wound management.

Medicinal Plants from Latin America with Wound Healing Activity: Ethnomedicine, Phytochemistry, Preclinical and Clinical Studies—A Review

Latin America is a multicultural region with ancient traditional medicine. There is extensive knowledge of the use of medicinal plants for wound healing in this region. Nevertheless, many of these medicinal plants lack pharmacological, toxicological, and chemical studies. This review focuses on the ethnomedicinal, phytochemical, and pharmacological (preclinical and clinical) studies of medicinal plants with wound healing activity, from Latin America. An electronic database search was conducted by consulting scientific articles and books. A total of 305 plant species with wound healing activity were recorded, based on traditional medicine. Most medicinal plants used in wound healing in Latin America are topically administered; their methods of preparation are mainly by water infusion from aerial parts. Only thirty-five percent of medicinal plants used in traditional medicine for wound healing have been experimentally validated for their pharmacological effects, and the wound healing activity of five medicinal plants has been studied in clinical trials. In all, 25 compounds (mostly terpenes and flavonoids) have been isolated from medicinal plants with wound healing activity; therefore, extensive work is necessary for a multidisciplinary approach to evaluate the wound healing effects of medicinal plants in Latin America. The mechanism of action of medicinal plants, their toxicological actions on the skin, and their bioactive compounds, have yet to be investigated. This review on the ethnomedicinal, phytochemical, and pharmacological studies, of medicinal plants from Latin America with wound healing activity, offers promising data for further studies, as well as providing new insights into their possible role in wound care.

A Comprehensive Review of Natural Compounds for Wound Healing: Targeting Bioactivity Perspective

Wound healing is a recovering process of damaged tissues by replacing dysfunctional injured cellular structures. Natural compounds for wound treatment have been widely used for centuries. Numerous published works provided reviews of natural compounds for wound healing applications, which separated the approaches based on different categories such as characteristics, bioactivities, and modes of action. However, current studies provide reviews of natural compounds that originated from only plants or animals. In this work, we provide a comprehensive review of natural compounds sourced from both plants and animals that target the different bioactivities of healing to promote wound resolution. The compounds were classified into four main groups (i.e., anti-inflammation, anti-oxidant, anti-bacterial, and collagen promotion), mostly studied in current literature from 1992 to 2022. Those compounds are listed in tables for readers to search for their origin, bioactivity, and targeting phases in wound healing. We also reviewed the trend in using natural compounds for wound healing.

Hormesis and Epidermal Stem Cells

This paper provides an assessment of hormetic dose responses in epidermal stem cells (EpSCs) in animal models and humans, with emphasis on cell proliferation and differentiation and application to wound healing and aging processes. Hormetic dose responses were induced by several agents, including dietary supplements (eg, luteolin, quercetin), pharmaceuticals (eg, nitric oxide), endogenous agents (eg, growth/differentiation factor 5), and via diverse chemical means to sustain steaminess features to retard aging and disease onset. While hormetic dose responses have been extensively reported in a broad spectrum of stem cells, this area has only been explored to a limited extent in EpSCs, principally within the past 5 years. Nonetheless, these findings provide the first integrated assessment of hormesis and EpSC biology within the context of enhancing key functions such as cell proliferation and differentiation and resilience to inflammatory stresses. This paper assesses putative mechanisms of hormetic responses in EpSCs and potential therapeutic applications to prevent dermatological injury and disease.

Wound Healing Properties of Jasione montana Extracts and Their Main Secondary Metabolites

The effects of different extracts obtained from Jasione montana L. (JM1-JM6) and their main metabolites on biological processes during wound healing were evaluated. The effect on wound closure in the scratch test was established, and collagen type I synthesis and anti-inflammatory effects were assessed by flow cytometry in a human dermal fibroblast model (PCS-201-012). Additionally, the antioxidant activity (DPPH and FRAP) and degree of inhibition of elastase participating in the proliferation processes of skin fibroblasts were determined in an in vitro model. The extracts and fractions were analyzed using high-performance liquid chromatography-photodiode array detection (HPLC-PDA) to quantitatively characterize their main polyphenolic compounds. The high antioxidant activity of the JM4-JM5 fractions correlated with the content of luteolin and its derivative 7-O-glucoside. Luteolin also showed the highest anti-elastase activity with an IC50 value of 39.93 ± 1.06 μg/mL, and its substantial content in the JM4 fraction presumably determines its activity (359.03 ± 1.65 μg/mL). At lower concentrations (<50 μg/mL) of all extracts, cell proliferation and migration were significantly stimulated after 24 h of treatment. The stimulation of cell migration was comparable with that of allantoin, which was used as a positive control. However, most of the tested extracts showed limited capacity to affect collagen type I biosynthesis. Moreover, the tested samples exhibited a complex effect on cytokine secretion, and the strongest anti-inflammatory activity through the moderation of IL-1β, IL-6 and IL-8 was observed for JM4 and luteolin. Based on the obtained results of the quantitative analysis, the anti-inflammatory activity of JM4 may be due to the high content of luteolin. In summary, extracts from J. montana, which is flavonoid-rich, promote the viability and accelerate the migration of fibroblasts as well as moderate oxidant and inflammatory processes and elastase activity. Hence, they may be potentially useful for topical therapeutic applications to stimulate the wound healing process.

Topical Application of Premna integrifolia Linn on Skin Wound Injury in Rats Accelerates the Wound Healing Process: Evidence from In Vitro and In Vivo Experimental Models

Background

When the skin and tissues within the body are injured, the healing process begins. Medicinal herbs have been used to cure wounds since time immemorial. The antimicrobial and antioxidant activity possessed by P. integrifolia may accelerate wound healing.

Objectives

To assess the wound healing activity of Premna integrifolia extract (PIE) by employing in-vivo experimental animal models and an in-vitro migration scratch assay. Furthermore, to assess its cytotoxicity using the MTT assay.

Methods

Wistar albino rats were used for the in vivo wound healing models. The animals were divided into four groups at random: Group I was untreated. Group II was vehicle control (ointment base). Group III was PIE ointment (5% W/W). Group IV was standard (povidone-iodine ointment) (5% W/W). The ointments were applied directly to the wounds as described above until they healed completely. The wound contraction percentage and tensile strength were calculated. The MTT test was used to determine the viability of the test extract against the fibroblast cells. The scratch assay was used in vitro to determine the wound healing potential of the test drug. P ≤ 0.05 values were considered statistically significant.

Results

Premna integrifolia extract did not possess any noticeable cytotoxicity to the cell line and showed an IC50 of 185.98 μg/ml. The wound contraction potential of PIE ointment-treated animals was considerably greater (P ≤ 0.001) on days 4, 8, 12, 16, and 20 when compared to the control group. The percentage of wound contraction on day 20 was 99.92% in PIE-treated animals compared to 83.23% in untreated animals. Compared to the untreated group, the duration of full epithelization was significantly (P ≤ 0.01) shorter in the test group. When compared to the incision control group, the animals treated with PIE ointment had significantly higher (P ≤ 0.001) tensile strength. In addition, animals given the test drug had a significant (P ≤ 0.001) increase in total protein and hydroxyproline. In the in vitro scratch assay, test drug-treated cells demonstrated greater cell migration. Histology images confirmed that the test drug-treated group had epithelial tissue proliferation and keratinization.

Conclusion

The current study found that Premna integrifolia improved wound healing activity both in vitro and in vivo. These findings indicate that Premna integrifolia extract has wound-healing potential and could be a viable source of nutraceuticals with wound-healing properties.

Natural Products for the Prevention and Control of the COVID-19 Pandemic: Sustainable Bioresources

Background: The world has been unprecedentedly hit by a global pandemic which broke the record of deadly pandemics that faced humanity ever since its existence. Even kids are well-versed in the terminologies and basics of the SARS-CoV-2 virus and COVID-19 now. The vaccination program has been successfully launched in various countries, given that the huge global population of concern is still far behind to be vaccinated. Furthermore, the scarcity of any potential drug against the COVID-19-causing virus forces scientists and clinicians to search for alternative and complementary medicines on a war-footing basis. Aims and Objectives: The present review aims to cover and analyze the etiology and epidemiology of COVID-19, the role of intestinal microbiota and pro-inflammatory markers, and most importantly, the natural products to combat this deadly SARS-CoV-2 virus. Methods: A primary literature search was conducted through PubMed and Google Scholar using relevant keywords. Natural products were searched from January 2020 to November 2020. No timeline limit has been imposed on the search for the biological sources of those phytochemicals. Interactive mapping has been done to analyze the multi-modal and multi-target sources. Results and Discussion: The intestinal microbiota and the pro-inflammatory markers that can serve the prognosis, diagnosis, and treatment of COVID-19 were discussed. The literature search resulted in yielding 70 phytochemicals and ten polyherbal formulations which were scientifically analyzed against the SARS-CoV-2 virus and its targets and found significant. Retrospective analyses led to provide information about 165 biological sources that can also be screened if not done earlier. Conclusion: The interactive analysis mapping of biological sources with phytochemicals and targets as well as that of phytochemical class with phytochemicals and COVID-19 targets yielded insights into the multitarget and multimodal evidence-based complementary medicines.

Investigation of Angiogenesis and Wound Healing Potential Mechanisms of Zinc Oxide Nanorods

The angiogenesis process is an essential issue in tissue engineering. Zinc oxide nanorods are biocompatible metals capable of generating reactive oxygen species (ROS) that respond to induced angiogenesis through various mechanisms; however, released Zn (II) ions suppress the angiogenesis process. In this study, we fabricated green ZnO nanorods using albumin eggshell as a bio-template and investigate its angiogenic potential through chorioallantoic membrane assay and excision wound healing assay. This study demonstrated that angiogenesis and wound healing processes depend on pro-angiogenic factors as VEGF expression due to ZnO nanorods' exiting. Angiogenesis induced via zinc oxide nanorods may develop sophisticated materials to apply in the wound healing field.

Phytochemical Screening of Himatanthus sucuuba (Spruce) Woodson (Apocynaceae) Latex, In Vitro Cytotoxicity and Incision Wound Repair in Mice

Himatanthus sucuuba, also known as "Bellaco caspi", is a medicinal plant whose latex, stem bark, and leaves possess phenolic acids, lupeol, β-dihydro-plumbericinic acid, plumericin, and plumeride, among other components. Some of these have been linked to such biological activities as antiulcer, anti-inflammatory, and wound healing. The aim of this study was to determine the phytochemical compounds of H. sucuuba latex, as well as its in vitro cytotoxicity and wound healing effect in mice. Latex was collected in the province of Iquitos, Peru. Phytochemical analysis was carried out with UPLC-ESI-MS/MS. The cytotoxicity was evaluated on two colon tumor cell lines (SW480 and SW620) and non-malignant cells (human keratinocytes, HaCaT, and Chinese hamster ovary, CHO-K1). The mice were distributed into two groups, as follows: Group I-control (n = 10; without treatment); II-(n = 10) H. sucuuba latex; wounds were induced with a scalpel in the dorsal-cervical area and treatments were applied topically twice a day on the incision for 10 days. Molecular docking was carried out on the glycogen synthase kinase 3β protein. Twenty-four chemical compounds were determined, mainly flavonoid-type compounds. Latex did not have a cytotoxic effect on tumor cells with IC₅₀ values of more than 500 µg/mL. The latex had a regenerative effect on wounds in mice. Acacetin-7-O-neohesperidoside had the best docking score of -9.9 kcal/mol. In conclusion, H. sucuuba latex had a wound healing effect in mice, as confirmed by histological study. However, a non-cytotoxic effect was observed on colon tumor cells SW480 and SW620.

Paving Luteolin Therapeutic Potentialities and Agro-Food-Pharma Applications: Emphasis on In Vivo Pharmacological Effects and Bioavailability Traits

Luteolin is a naturally occurring secondary metabolite belonging to the class of flavones. As many other natural flavonoids, it is often found in combination with glycosides in many fruits, vegetables, and plants, contributing to their biological and pharmacological value. Many preclinical studies report that luteolin present excellent antioxidant, anticancer, antimicrobial, neuroprotective, cardioprotective, antiviral, and anti-inflammatory effects, and as a consequence, various clinical trials have been designed to investigate the therapeutic potential of luteolin in humans. However, luteolin has a very limited bioavailability, which consequently affects its biological properties and efficacy. Several drug delivery strategies have been developed to raise its bioavailability, with nanoformulations and lipid carriers, such as liposomes, being the most intensively explored. Pharmacological potential of luteolin in various disorders has also been underlined, but to some of them, the exact mechanism is still poorly understood. Given the great potential of this natural antioxidant in health, this review is aimed at providing an extensive overview on the in vivo pharmacological action of luteolin and at stressing the main features related to its bioavailability, absorption, and metabolism, while essential steps determine its absolute health benefits and safety profiles. In addition, despite the scarcity of studies on luteolin bioavailability, the different drug delivery formulations developed to increase its bioavailability are also listed here.

Assessing the mechanisms of action of natural molecules/extracts for phase-directed wound healing in hydrogel scaffolds

Hydrogels are proving to be very versatile as wound healing devices. In addition to their capabilities of providing a moist cellular environment and adaptive mechanical properties mimicking the extracellular matrix, they allow the incorporation of small molecules, which have potential impacts on cellular behaviour, in their nanostructures. This strategy can allow for specific targeting of the different stages of wound healing namely hemostasis, inflammation, and proliferative and remodelling phases. The latter include interlinked processes such as angiogenesis, collagen synthesis, growth factor release, collagen maturation and re-epithelialization. In this review, we attempt to match the mechanisms of action of natural molecules/extracts to the different stages of wound healing so that they can be used in a novel approach of multiphase-directed tissue regeneration using loaded hydrogel scaffolds.

Wound healing properties of flavonoids: A systematic review highlighting the mechanisms of action

BACKGROUND

Flavonoids are a class of compounds with a wide variety of biological functions, being an important source of new products with pharmaceutical potential, including treatment of skin wounds.

PURPOSE

This review aimed to summarize and evaluate the evidence in the literature in respect of the healing properties of flavonoids on skin wounds in animal models.

STUDY DESIGN

This is a systematic review following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

METHODS

This was carried out through a specialized search of four databases: PubMed, Scopus, Web of Science and Embase. The following keyword combinations were used: "flavonoidal" OR "flavonoid" OR "flavonoidic" OR "flavonoids" AND "wound healing" as well as MeSH terms, Emtree terms and free-text words.

RESULTS

Fifty-five (55) articles met the established inclusion and exclusion criteria. Flavonoids presented effects in respect of the inflammatory process, angiogenesis, re-epithelialization and oxidative stress. They were shown to be able to act on macrophages, fibroblasts and endothelial cells by mediating the release and expression of TGF-β1, VEGF, Ang, Tie, Smad 2 and 3, and IL-10. Moreover, they were able to reduce the release of inflammatory cytokines, NFκB, ROS and the M1 phenotype. Flavonoids acted by positively regulating MMPs 2, 8, 9 and 13, and the Ras/Raf/MEK/ERK, PI3K/Akt and NO pathways.

CONCLUSION

Flavonoids are useful tools in the development of therapies to treat skin lesions, and our review provides a scientific basis for future basic and translational research.

Luteolin and hormesis

The present paper provides the first integrated assessment of the capacity of luteolin to induce hormetic dose responses. It was shown that luteolin induced hormetic responses in multiple biological systems, including enhancing neuroprotection in various experimental model disease systems, improving wounding healing, especially in experimental models of high-risk population subgroups, such as diabetics, as well as enhancing osteogenesis in models of osteoporosis. The mechanistic basis for the luteolin-induced hormetic dose responses has been demonstrated to commonly involve the upregulation of the nuclear factor erythroid-derived 2-like 2 (Nrf2), which mediates the extensive range of anti-inflammatory effects induced by luteolin in multiple cell types and organ systems.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Therapeutic Potential of Luteolin on Impaired Wound Healing in Streptozotocin-Induced Rats

Long-term hyperglycemia may lead to diabetic microvascular and macrovascular complications that can affect the peripheral vascular system, particularly in wound healing capacity. Impaired angiogenesis and delayed wound healing are significant clinically. Luteolin (3', 4', 5, 7-tetrahydroxyflavone) is a naturally occurring flavonoid that is ubiquitously found in plants. Recent evidence has shown that luteolin is an anti-inflammatory and anti-oxidative agent. However, the effect of systemic luteolin administration on diabetic wound restoration remains unclear. Herein, we explored the effectiveness of luteolin for improving delayed and impaired healing of skin wound and further clarified the underlying mechanisms. The results indicated that luteolin significantly attenuates blood glucose concentration, improves impaired healing and accelerates re-epithelization of skin wound in streptozotocin (STZ)-induced diabetic rats. Histopathological staining and immunoblotting revealed an inhibitory effect of luteolin on inflammatory cell and cytokine production. We also observed remarkable decreases in protein expressions of inflammatory factors including matrix metalloproteinase (MMP)-9, tumor necrosis factor (TNF)-α, interleukin (IL-6), and IL1-β and downregulation of nuclear factor (NF)-κB, as well as increases in anti-oxidative enzymes such as superoxide dismutase 1 (SOD1) and glutathione peroxidase (GSH-Px) induced by nuclear factor erythroid 2-related factor (Nrf)-2 following luteolin supplementation. Furthermore, luteolin decreased the expression of vascular endothelial growth factor (VEGF) and increased the expression of ubiquitin carboxy-terminal hydrolase (UCH)-L1, as evidenced by angiogenesis and neuronal regeneration in completely healed wound. In conclusion, systemic administration of luteolin promotes wound restoration by ameliorating inflammation and oxidative stress through the inactivation of NF-κB and upregulation of Nrf2 in STZ-induced diabetic rats.

Opening eyes to therapeutic perspectives of bioactive polyphenols and their nanoformulations against diabetic neuropathy and related complications

Introduction: Diabetic neuropathy (DN) is one of the major complications arising from hyperglycaemia in diabetic patients. In recent years polyphenols present in plants have gained attention to treat DN. The main advantages associated with them are their action via different molecular pathways to manage DN and their safety. However, they failed to gain clinical attention due to challenges associated with their formulation development such as lipophilicity,poor bioavailability, rapid systemic elimination, and enzymatic degradation.Area covered: This article includes different polyphenols that have shown their potential against DN in preclinical studies and the research carried out towards development of their nanoformulations in order to overcome aforementioned issues.Expert opinion: In this review various polyphenol based nanoformulations such as nanospheres, self-nanoemulsifying drug delivery systems, niosomes, electrospun nanofibers, metallic nanoparticles explored exclusively to treat DN are discussed. However, the literature available related to polyphenol based nanoformulations to treat DN is limited. Moreover, these experiments are limited to preclinical studies. Hence, more focus is required towards  development of nanoformulations using simple and single step process as well as inexpensive and non-toxic excipients so that a stable, scalable, reproducible and non-toxic formulation could be achieved and clinical trials could be initiated.

Exploration of the role of a lithophytic fern, Pteris vittata L. in wound tissue regeneration and remodelling of genes in hyperglycaemic rat model

Background

In hyperglycemic conditions like diabetes, impaired wound healing occurs due to endothelial damage, dysfunction of leukocyte, decreased phagocytosis and secondary infection which may lead to amputation and debility. Ethnomedicinally,Pteris vittataL. (PV) is used for wound healing. This fern is arsenic hyper-accumulator but its therapeutic aspect is still unexplored. Hence, the present study was put forth to study its aqueous extract and ethanolic extract in diabetic wound healing.

Methods

Rats were divided into diabetic control, povidine iodine (PI) treated, ethanolic and aqueous extracts of PV treated groups (n = 6). Circular excision wound closure was observed for 15 days with and without treatment. After study completion, skin was divided into four sections wherein first section was homogenized for collagen, hydroxyproline and hexosamine assay. Second, third and fourth sections were used for antioxidant assay, gene expression and histopathology. Column purified fraction of ethanolic extract of PV was subjected to High Performance Liquid Chromatography, Fourier-transform infrared spectroscopy, Nuclear Magnetic Resonance and Mass spectroscopy. Data obtained were analyzed using one way analysis of variance and expressed as Mean ± SD.

Results

The percentage difference in wound area of day 15 to day 0 showed 65% wound contraction in diabetic control rats. The percentage reduction in wound area showed by PI and extracts of PV were 79% and 85% respectively. Statistical significant increase in collagen, hydroxyproline and hexosamine was observed in the test groups as compared to disease control and PI treated rats. Similarly, statistical significant increases in antioxidant enzymes were observed in the treated groups with decrease in lipid peroxidation. Treatment of rats with PI and two extracts of PV up-regulated Matrix Metalloprotein-9, Collagenase-2 and VEGF-1 and down regulated Tumor Necrosis Factor- α and Interleukin-6. Histopathology in diabetic rats showed incomplete scab formation with haemorrhages which were absent in treated rats. Spectral data showed presence of polyphenolic compounds, fatty acids and ascorbic acid.

Conclusion

Alternative and complimentary management based on herbal biotherapy which can promote angiogenesis, increase collagen and lower the levels of reactive oxygen species are warranted for healing of wounds in hyperglycaemic conditions which were achieved by two extracts of PV.

Evaluation of in vivo wound healing activity of Moroccan Citrus reticulata peel extract

Background

Citrus reticulata is one of the most cultivated fruit with great benefits for humans in the world. Citrus reticulata peel has several biological activities within them hypoglycemic, hepatoprotective, antimicrobial and antioxidant. The present study emphasizes on the in vivo wound healing and in vitro antimicrobial and antioxidant activities of Citrus reticulata peel extract.

Methods

Forty albino mice (23–29 g) of either sex were divided into four groups. The test groups were treated with experimental ointment (0.5% and 10% of methanolic extract), negative control were treated with Vaseline and the positive control were treated with silver sulfadiazine. Burn wounds were induced on dorsal area of mice bodies. Wound area measurement was carried out every day during 22 days. Biochemical screening was performed to identify possible compounds. Antioxidant and antimicrobial activities were also determined.

Results

Significant wound healing activity was observed with topical application of Citrus reticulata peel extract. Wound area reduction at day 16 of treatment was 100% for both treated groups (0.5% and 10%) when compared to positive and negative control it was 100% and 98.32% respectively at day 22. Furthermore higher rate of wound contraction (100% on 16th day) was observed for both treated groups.

The result of biochemical screening showed that C. reticulata peel is characterized by highest amount of total polyphenols (13.19 mg/g), flavonoids (4.07 mg/g), vitamin C (13.20 mg/g), carotenoids (0.032 mg/g) and lowest content of macronutrients (Proteins: 0.40%, reducing sugars: 7.21%; lipids: 1.5%). Additionally C. reticulata peel exhibited remarkable antioxidant activity using DPPH and phosphomolybdate methods as well as the extract possess antimicrobial effect against pathogen bactria.

Conclusion

The findings from this research indicated that Citrus reticulata peel extract is effective in inhibiting the growth of pathogen bacteria and could be of therapeutic potentials for wound healing.

Polydopamine Antioxidant Hydrogels for Wound Healing Applications

Antioxidants are known to improve the wound healing process and are researched as a therapeutic strategy to treat chronic wounds. Dopamine is a known neurotransmitter with antioxidant properties that can be polymerized to form polydopamine (PDA). Herein, polydopamine is demonstrated as an antioxidant biomaterial. In prior work, we developed methodology to prepare hydrogels by crosslinking polysaccharides with polyamines via epichlorohydrin and NaOH. Using this previously developed methodology, dextran hydrogels crosslinked with polydopamine were prepared. Darkening of the gels indicated the increasing incorporation of polydopamine within the hydrogels. In addition to basic pH, polydopamine can be formed by reaction with polyethylene imine (PEI), which results in PEI-PDA copolymer. Dextran was similarly crosslinked with the PEI-PDA copolymer and resulted in sturdier, darker gels, which had more polydopamine incorporated. Hydrogel morphology and strength were dependent on the feed ratios of dopamine. Antioxidant activity of polydopamine containing hydrogel was confirmed and shown to be dependent on the amount of dopamine used in hydrogel synthesis. Hydrogels with 0.5 dopamine to dextran feed ratio scavenged 78.8% of radicals in a 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant assay while gels with no dopamine scavenged only 1.4% of radicals. An ex vivo wound healing assay showed considerable cell migration with the PEI-PDA containing hydrogel.

Cuscuta reflexa Roxb. Expedites the Healing Process in Contact Frostbite

Frostbite is caused due to extreme vulnerability to cold, resulting in damage of deeper and superficial tissues alike. In this study, we report the anti-inflammatory and wound-healing properties of aqueous methanolic extract of Cuscuta reflexa (Cs.Cr) against contact frostbite. Thirty rats were divided into five groups including three treatment groups with increasing doses of Cs.Cr, a standard drug group receiving acetylsalicylic acid (ASA), and a metal bar-induced frostbite group. Frostbite injury was induced by a 3 × 3.5 cm metal bar frozen up to -79°C on shaved skin for continuous 3 minutes. Wounded area percentages were recorded to measure the healing rate in response to Cs.Cr administration. Haematological parameters and malondialdehyde content were also noted. On treatment with Cs.Cr, the healing rate is drastically increased and lipid peroxidation product malondialdehyde was decreased in a dose-dependent manner. Results were compared with frostbite and ASA (standard drug group). These results indicate that Cs.Cr possesses excellent wound-healing properties against frostbite injury and can prove to be a prospective compound in such conditions.

Natural tyrosine kinase inhibitors acting on the epidermal growth factor receptor: Their relevance for cancer therapy

Epidermal growth factor receptor (EGFR), also known as ErbB-1/HER-1, plays a key role in the regulation of the cell proliferation, migration, differentiation, and survival. Since the constitutive activation or overexpression of EGFR is nearly found in various cancers, the applications focused on EGFR are the most widely used in the clinical level, including the therapeutic drugs of targeting EGFR, monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs).Over the past decades, the compounds from natural sources have been a productive source of novel drugs, especially in both discovery and development of anti-tumor drugs by targeting the EGFR pathways as the TKIs. This work presents a review of the compounds from natural sources as potential EGFR-TKIs involved in the regulation of cancer. Moreover, high-throughput drug screening of EGFR-TKIs from the natural compounds has also been summarized.

Hancornia speciosa serum fraction latex stimulates the angiogenesis and extracellular matrix remodeling processes

The Hancornia speciosa latex reveals angiogenic, osteogenic, and anti-inflammatory properties, which present its potential for developing of wound healing drugs; however, the latex compounds responsible for angiogenesis remain unknown. One strategy to screen these active compounds is evaluation of latex fractions. This study aimed to obtain different fractions of latex and evaluate its angiogenic activity separately using the chick chorioallantoic membrane (CAM) assay. The serum (SE) fraction was responsible for angiogenesis, which was subject to biochemical characterization and computational simulations in order to understand the contribution of H. speciosa latex in wound healing process. Our results revealed weak antioxidant potential and absence of antimicrobial activity in the SE fraction. Phytochemical analysis identified chlorogenic acids (CGA) as the main compound of SE fraction. CGA bioactivity predictions identify different molecules associated with extracellular matrix (ECM) remodeling, such as metalloproteinases, which also are overexpressed in our CAM assay experiment. Docking simulations revealed the interactions between CGA and matrix metalloproteinase 2. In conclusion, SE latex fraction stimulates angiogenesis and may influence ECM remodeling. These properties may contribute to the wound healing process, and also confirm the widespread use of this plant.

Stellaria media (L.) Vill.- A plant with immense therapeutic potentials: phytochemistry and pharmacology

Stellaria media Vill. is a representative of Caryophyllaceae family. The plant is widely dispersed all over the world and has been used as therapeutic substance since time immemorial. This review is aimed at exploring the chemical constituents and pharmacological activities of S. media. The findings revealed important secondary metabolites such as flavonoid, oligosaccharide stellariose, anthraquinone derivatives, fatty acid, steroid saponins and phenolic compounds. These bioactive metabolites displayed diverse pharmacological activities such as anti-obesity, antifungal, antibacterial, antioxidant, anti-proliferative, anti-inflammatory, analgesic, antidiabetic and anxiolytic activities. All findings revealed that S. media is a major species of Caryophyllaceae family. However, bioactive constituents and pharmacological potential of are not well appraised. Hence, extracts with established pharmacological activities should be subjected to bioassay guided isolation so as to obtain compounds with novel structural moieties prior to toxicogenetic appraisals.

Bioassay-Guided Different Extraction Techniques of Carica papaya (Linn.) Leaves on In Vitro Wound-Healing Activities

Herbal plants are traditionally utilized to treat various illnesses. They contain phytochemicals that can be extracted using conventional methods such as maceration, soxhlet, and boiling, as well as non-conventional methods including ultrasonic, microwave, and others. Carica papaya leaves have been used for the treatment of dengue, fungal, and bacterial infections as well as an ingredient in anti-aging products. Phytochemicals analysis detected the presence of kaempferol, myricetin, carpaine, pseudocarpaine, dehydrocarpaine I and II, ferulic acid, caffeic acid, chlorogenic acid, β-carotene, lycopene, and anthraquinones glycoside. Conventional preparation by boiling and simple maceration is practical, simple, and safe; however, only polar phytochemicals are extracted. The present study aims to investigate the effects of three different non-conventional extraction techniques (ultrasonic-assisted extraction, reflux, and agitation) on C. papaya phytochemical constituents, the antioxidant capacity, and wound-healing activities. Among the three techniques, the reflux technique produced the highest extraction yield (17.86%) with the presence of saponins, flavonoids, coumarins, alkaloids, and phenolic metabolites. The reflux technique also produced the highest 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging with an IC50 value of 0.236 mg/mL followed by ultrasonic-assisted extraction (UAE) (IC50: 0.377 mg/mL) and agitation (IC50: 0.404 mg/mL). At tested concentrations (3.125 µg/mL to 500 µg/mL), all extracts do not exhibit a cytotoxicity effect on the human skin fibroblast, HSF1184. Interestingly, reflux and UAE were active fibroblast proliferators that support 85% (12.5 µg/mL) and 41% (6.25 µg/mL) better cell growth, respectively. Additionally, during the early 24 h of the scratch assay, the migration rate at 12.5 µg/mL was faster for all extracts with 51.8% (reflux), 49.3% (agitation), and 42.5% (UAE) as compared to control (21.87%). At 48 h, proliferated cells covered 78.7% of the scratch area for reflux extract, 63.1% for UAE, 61% for agitation, and 42.6% for control. Additionally, the collagen synthesis was enhanced for 31.6% and 65% after 24 and 48 h of treatment for reflux. An HPLC-MS/MS-QTOF (quadruple time-of-flight) analysis of reflux identified nine phytochemicals, including carpaine, kaempferol 3-(2G-glucosylrutinoside), kaempferol 3-(2″-rhamnosylgalactoside), 7-rhamnoside, kaempferol 3-rhamnosyl-(1->2)-galactoside-7-rhamnoside, luteolin 7-galactosyl-(1->6)-galactoside, orientin 7-O-rhamnoside, 11-hydroperoxy-12,13-epoxy-9-octadecenoic acid, palmitic amide, and 2-hexaprenyl-6-methoxyphenol. The results suggested that reflux was the best technique as compared to ultrasonic and agitation.

Evaluation of wound healing effect of chitosan-based gel formulation containing vitexin

Acute or chronic wounds are one of the most common health problems worldwide and medicinal drugs or traditional remedies are often used in wound healing. Further studies regarding wound treatment are rapidly continuing. Vitexin is a phenolic compound, which is found in many medicinal plants, has different pharmacological effects such as anti-inflammatory, analgesic and antioxidant. In the present study, it is aimed to investigate the wound healing effect of formulation prepared as chitosan-based gel with vitexin in vivo and in vitro. Cytotoxicity and wound healing assays were used for in vitro and excisional wound model is used for in vivo studies. Extracted tissues from wound area were histologically examined. Wound healing process was monitored on 7, 14 and 21st days. When wound construction was evaluated, chitosan-based gel formulation containing vitexin demonstrated significant effect compared to control group. Histological examinations demonstrated that skin regeneration was promoted by vitexin formulation. Significant cell proliferation was observed with vitexin/chitosan dispersion in the wound healing assay performed with NIH 3T3 and HaCaT cells. In conclusion, our test substance chitosan-based gel formulation containing vitexin significantly accelerated wound healing both in vivo and in vitro.

Effect of ethanol extract from Lactobacillus plantarum TWK10-fermented soymilk on wound healing in streptozotocin-induced diabetic rat

Wound healing is a highly dynamic phenomenon comprising numerous coordinated steps including homeostasis/coagulation, inflammation, migration, proliferation, and remodeling. Diabetes mellitus (DM) is a multisystem chronic epidemic that prolongs inflammation in wounds and is associated with impaired healing. This study aimed to investigate the effect of an ethanol extract from Lactobacillus plantarum TWK10 (TWK10)-fermented soymilk on wound healing. The anti-inflammatory effects of the ethanol extract of TWK10-fermented soymilk on lipopolysaccharide-stimulated RAW264.7 macrophage cells were examined. The ethanol extract of TWK10-fermented soymilk (100 µg/mL) significantly decreased nitric oxide production from 11.34 ± 0.74 μM to 8.24 ± 2.02 µM (p < 0.05) and enhanced proliferation in Detroit 551 cells cultured in high-glucose medium; the cell number peaked at 128.44 ± 7.67% (compared to the untreated control) at 600 µg/mL. An ethanol extract of TWK10-fermented soymilk + vaseline-treated rat model of streptozotocin-induced diabetic wounds was generated herein, and the following groups were formed herein: normal control (NC), blank control (BC), low dose group (LD, 0.24 mg/wound), intermediate dose (MD, 0.48 mg/wound), and high dose (HD, 2.40 mg/wound). On day 14 after wound infliction, the wound area in the LD, MD, and HD groups was significantly decreased to 10.2, 8.4, and 8.5% respectively (p < 0.05). Moreover, in the LD, MD, and, HD groups, tumor necrosis factor-α, interleukin 6, and matrix metalloproteinase-9 were downregulated in the wounded skin. These results show that the topical application of the ethanol extract of TWK10-fermented soymilk is beneficial for enhancing wound healing and for the closure of diabetic wounds.

Effect of alerce (Fitzroya cupressoides) cell culture extract on wound healing repair in a human keratinocyte cell line

BACKGROUND

Fitzroya cupressoides, commonly known as alerce, is an endemic conifer unique to southern South America. Alerce wood is renowned for its durability and resistance to biological degradation due to the presence of a particular class of secondary metabolite. Alerce extracts have been used in traditional medicine for different skin lesion treatments.

AIMS

To develop a cell culture system to produce alerce extract and evaluate its cytotoxicity and effects on in vitro wound healing.

METHODS

Cell cultures and aqueous extracts were prepared from alerce needles. Cytotoxicity was evaluated in keratinocytes (HaCaT line) and melanocites (C32 line) using the XTT assay. Wound healing was assayed with the scratch test in HaCaT cells, using mitomycin C to evaluate the role of cell division in the wound closure.

RESULTS

Alerce cell culture extract has a significant effect on wound healing at different concentrations. No positive effects on the viability of normal and cancerous skin cells were observed. These results suggest that alerce extracts stimulate cell division in human skin epidermal cells in the context of wound repair.

CONCLUSIONS

Bioactive compounds extracted from alerce cell cultures show promise as ingredients in dermocosmetic formulations, but further clinical studies are required to support these findings at the tissue level.

Topical Application of Teucrium polium Can Improve Wound Healing in Diabetic Rats

Diabetic foot ulcer is one of the major complications among diabetic patients. Several studies have shown that the extract of Teucrium polium (T. polium) is effective in the treatment of diabetic and non-diabetic wounds, as well as burn wounds. The aim of current study was to assess the wound healing activity of T. polium extract ointment in diabetic rats. Sixty-four male Wistar rats were induced diabetes with alloxan injection (125 mg/kg) and surgical wound induced. The rats were divided into 8 groups of eight rats each: control group, eucerin group, phenytoin group, 2%, 3%, 4%, 5% and 10% T. polium groups. The ointment was dressed on the wound twice a day. The process of wound healing was screened by macroscopy and digitalization on days 14 and 21 and until complete wound healing. There was no infection in the wounds of rats in any groups. The process of wounds healing of the 2%, 3%, 4%, 5%, and 10% T. polium ointments, with phenytoin ointment and base ointment (eucerin) on day 14 and 21, showed that the significant difference between the treatment groups with 4% (P = 0.003), 5% (P = 0.001), 10% (P = 0.001) T. polium ointment and phenytoin ointment group (P = 0.001) compared to eucerin group. The results of this study showed that T. polium extract ointment with a 10% ointment accelerates the wound healing process in diabetic rats and is comparable to the phenytoin group.